Irritation or damage to lumbar nerve roots referred to as lumbar radiculopathy or sciatica is a very common clinical entity with a lifetime prevalence of 1-3% in the adult population. Lumbar radiculopathy typically causes back pain and sharp, shooting pain in the leg(s). Despite its prevalence and disabling characteristics, sciatica has never been selectively studied in drug trials. We propose to study the anti-epileptic drug topiramate, which combines multiple potential analgesic actions including sodium channel blockade, GABA agonist-like effects and AMPA/kainate glutamate receptor blockade. Patients will include men and women of all ethnic backgrounds between the ages of 18 and 75 who have had signs and symptoms of sciatica for 3 months or more.